The following are being investigated: the nature of naturally occurring and artificially produced mutant polygenes; chromosomal, isozyme and viability variation in natural populations; effective population sizes; linkage disequilibria of isozyme and chromosomal polymorphisms; loads, dominance, and genetic variances of viability polygenes; selective modes of enzymatic variants; evolutionary diversity and racial classification; distance measures; analyses of gene frequencies of natural populations; a probabilistic description of the evolution of linked neutral genes; mutation-selection balance of detrimental genes with migration in finite populations; and numbers of descendent genes and zygotes of detrimental mutants. Research methods are analytical and experimental. Experimental researches are conducted mostly with Drosophila and maize.